1. Field of the Invention
This invention relates to novel lithium dicyclopentadienyl titanium hydride compositions, useful as catalysts in the conversion of ethylene to 1-butene, and processes for their synthesis.
2. Brief Description of the Background of the Invention Including Prior Art
As a result of the decreasing amounts of energy reserves in the world, particularly petroleum feedstocks, coupled with sharply rising increases in energy demands in the heavily industrialized regions of the world, intense research efforts are being conducted in developing new processes and new catalysts for synthesizing energy-yielding materials.
One aspect of this research is directed to increasing the octane number of automotive gasoline in order to increase the efficiency of fuel utilization in the internal combustion engine. "Polymer gas", a mixture produced by polymerizing 1-butene, 2-butene and ethylene, or mixtures thereof, can be added to automotive gasoline in order to increase the octane number, and thus, the efficiency of fuel utilization.
The starting component, 1-butene, can be produced industrially, in heterogeneous processes by the catalytic dehydrogenation of n-butane over chromic oxide on alumina catalyst at elevated temperatures, or by thermal and catalytic cracking of petroleum and natural gas fractions. See "Encyclopedia of Chemical Technology", by Kirk-Othmer, Second Edition, Volume 3, pp. 833-834, Interscience Publishers (1964).
Methods are also known for producing 1-butene from the catalytic dimerization of ethylene in solutions of Ziegler-type catalysts as described in German Pat. No. 1,034,169 (1958), Chem. Abstr. 54, 2087a; and German Pat. No. 1,039,055 (1958), Chem. Abstr. 54, 25992h.
New catalysts, which are inexpensively and easily prepared and which can homogeneously catalyze the dimerization of ethylene to 1-butene are desired in order to overcome the known disadvantages of the use of heterogeneous catalysts. Such disadvantages include surface poisoning effects, criticality of particle size, activation procedures and the like.
Novel cyclopentadienyl titanium complexes and nitrogen product complexes are described in the references: U.S. Pat. No. 3,776,932 (1973), U.S. Pat. No. Re. 29,368 (1977), U.S. Pat. No. 4,024,169 (1977), and J. Amer. Chem. Soc., 98, 8072-8078 (1976), by Guido Pez (said patents being assigned to Allied Chemical Corp.), hereby incorporated by reference, as being capable of converting ethylene to mixtures of ethane, butane, 1-butene and 1,3-butadiene. However, no specific mention of cyclopentadienyl titanium lithium hydride type complexes is made in the above references.